California plans to buy only clean energy for its planned 800-mile system.

Fast and clean

That is high-speed rail’s environmental promise: fast and clean.

One of its most visible promoters is Andy Kunz, president and CEO of the U.S. High Speed Rail Association. Members include train operators, manufacturers and others.

“What’s most incredible about high-speed rail is that it’s a single investment that can simultaneously help solve climate change, congestion, energy security, energy efficiency, economic development, city revitalization, unemployment and loss of manufacturing,” Kunz said.

Skeptics question the benefits.

“Because high-speed rail will only capture a relatively small share of total passenger trips, it is also unlikely to make much difference in achieving greenhouse gas reduction targets and in reducing petroleum consumption,” the Congressional Research Office concluded last month.

High-speed trains through Texas would use their own tracks. Existing Amtrak service in Texas yields to freights.

Steve Mattingly, an associate professor of civil engineering at the University of Texas at Arlington, reached that conclusion in a study for the state last year.

Because intercity travel uses different power sources — electricity, gasoline and jet fuel — experts compare them with Btus, or British thermal units.

Running high-speed rail uses far less per passenger per mile than driving or flying. Critics often say that ignores energy to build the system. But the same applies to energy to build highways and airports.

It’s not known how much a Texas system would need.

The Electric Reliability Council of Texas, which runs most of Texas’ grid, is working on long-range forecasting for all demands, spokeswoman Robbie Searcy said.